Emery-Dreifuss Muscular Dystrophy (EDMD): Muscle Weakness and Heart Risks

Written by the Muscular Dystrophy Pakistan (MDP) content team. Based on information from GeneReviews, MedlinePlus Genetics, Muscular Dystrophy UK and published research (see sources below). Last updated: October 17, 2026.

"His elbows will not straighten fully." "He walks on his toes because his heels are tight." "The doctor found a very slow heartbeat." These can be the signs of Emery-Dreifuss muscular dystrophy (EDMD), a rare inherited condition that is unusual because it affects three things together: the joints, the muscles and, most importantly, the heart. The muscle weakness in EDMD is often slow and mild, so families sometimes focus only on the stiff joints. But the heart problems can be serious, and sometimes silent, which is why EDMD is a condition where knowing the diagnosis can protect a life. This guide explains EDMD in simple words: what it is, what causes it, how it is inherited, the symptoms, why the heart matters so much, how it is diagnosed and how it is managed.

Quick facts

• EDMD is a group of rare inherited conditions with a typical triad: early joint contractures, slowly progressive muscle weakness and heart rhythm problems.
• It can be inherited in an X-linked, autosomal dominant or, rarely, autosomal recessive pattern, depending on the gene.
• The main genes are EMD, FHL1 (X-linked) and LMNA (usually autosomal dominant).
• By adulthood, most people with EDMD develop heart problems, and these can occur even when muscle weakness is mild.
• A pacemaker or an implanted defibrillator can protect against sudden cardiac events, so regular heart checks are essential.
• There is no cure, but good heart care and joint care make a big difference.

What Is Emery-Dreifuss Muscular Dystrophy?

EDMD is named after the two doctors, Alan Emery and Fritz Dreifuss, who described it. It is a condition in which muscle weakness develops slowly, joints become tight early in life, and the heart's electrical system and muscle are affected. The weakness typically involves the upper arms and shoulders and the lower legs (a "humero-peroneal" pattern), and it usually progresses slowly over many years. EDMD is not contagious and nobody is to blame. It is caused by changes in genes.

The Three Main Features

1. Early joint contractures

Contractures are joints that become tight and cannot be fully straightened. In EDMD, they often appear in childhood or the teenage years, and often before noticeable muscle weakness. They typically involve the elbows, the Achilles tendons at the back of the ankles (causing toe walking), the neck and the spine, which becomes stiff.

2. Slowly progressive muscle weakness

Weakness and thinning of the upper arm and shoulder muscles and of the lower leg muscles. It can cause difficulty lifting objects, climbing stairs or running, and in some people foot drop. The weakness is often mild at first and progresses slowly. Some people with EDMD have little muscle weakness and are diagnosed because of the heart.

3. Heart involvement

This is the most important feature. The heart problems in EDMD are mainly conduction defects, which means that the electrical signals that tell the heart when to beat are disrupted. They can include a slow heartbeat (bradycardia), blocks in the heart's electrical pathway, atrial problems and, later, weakening of the heart muscle (cardiomyopathy). The heart effects often become noticeable in the teenage years or early adulthood, and by adulthood most people are affected. In some people, heart problems appear before any clear muscle weakness.

What Causes EDMD and How Is It Inherited?

EDMD is caused by changes in genes that make proteins of the nuclear envelope, the membrane that surrounds the nucleus of the cell. These proteins help to keep the nucleus stable, especially in cells that work hard under mechanical stress, such as muscle and heart cells. Several genes can be involved:

Type	Gene / protein	Inheritance
EDMD1 (X-linked)	EMD / emerin	X-linked recessive
EDMD6 (X-linked)	FHL1	X-linked recessive; female carriers may have symptoms, usually cardiac
EDMD2 and EDMD3	LMNA / lamin A/C	Usually autosomal dominant; rarely autosomal recessive
Other rarer types	SYNE1, SYNE2, SUN1, SUN2 and others	Mostly autosomal dominant; a few recessive

X-linked EDMD (EMD, FHL1): This mainly affects boys and men. A carrier mother has a 50% chance with each son of passing on the change and a 50% chance with each daughter of her being a carrier. Female carriers should be offered heart checks, because they can develop heart problems later in life.

Autosomal dominant EDMD (LMNA): One changed copy is enough. An affected person has a 50% chance of passing it to each child, boy or girl. LMNA-related disease has a higher risk of serious heart rhythm problems, and sometimes the heart is affected without major joint contractures. It can also appear as a new change in the family.

EDMD is not caused by cousin marriage, although the very rare recessive forms are more likely when parents are related.

Symptoms of EDMD

• Stiff elbows that cannot be straightened fully, tight ankles and toe walking, a stiff neck and a rigid spine
• Weakness and thinning of the upper arms, shoulders and lower legs
• Difficulty climbing stairs or lifting heavy objects, and tripping
• Tiredness and reduced stamina
• Heart symptoms: A slow heartbeat, palpitations, dizziness, fainting, unusual tiredness and breathlessness. These can be mild and unspecific, or severe. Complete heart block can cause fainting and, in the worst case, sudden death.

Important: Heart rhythm problems can exist without any symptoms. This is why heart checks are done regularly, even when the person feels well.

How Is EDMD Diagnosed?

• Examination: The doctor looks for the typical pattern of contractures and weakness and asks about relatives with heart problems, pacemakers or sudden death at a young age.
• CPK blood test: Usually normal or only mildly to moderately raised.
• Heart tests: ECG, a 24-hour heart rhythm recording (Holter), echocardiogram and sometimes cardiac MRI. These tests are essential at diagnosis and then regularly.
• Genetic testing: The key test. An EDMD gene panel looks at EMD, FHL1, LMNA and other related genes, and confirms the type, which guides heart care and family testing.
• Muscle biopsy: Rarely needed today. It can show a missing emerin protein in X-linked EDMD1 when genetic tests are not available.

EDMD can be mistaken for other conditions such as limb-girdle muscular dystrophy or Becker muscular dystrophy, so the genetic result matters.

Management and Care

There is no cure for EDMD at the moment. Care is built around the heart first, and is best given by a team: a neurologist, a heart rhythm specialist (cardiologist), an orthopaedic doctor and others as needed.

• Heart monitoring: Regular ECG, Holter and echocardiogram, usually at least once a year or as the cardiologist advises, starting from the time of diagnosis, and earlier in the teenage years.
• Pacemaker or defibrillator: When the heart's conduction system is affected, a pacemaker can protect against dangerously slow rhythms. In some people, especially with LMNA-related disease, an implantable cardioverter-defibrillator (ICD) is advised. Most people with X-linked EDMD1 will need a pacemaker at some point.
• Heart medicines: Medicines for heart failure and abnormal rhythms, and, in some rhythm problems, medicines to prevent blood clots and strokes, as decided by the cardiologist.
• Joints and spine: An orthopaedic doctor reviews tight joints, Achilles tightness and spine stiffness, and advises when treatment is needed.
• Breathing: Breathing tests from time to time, because a stiff spine and weak muscles can affect breathing in some people. Flu and pneumococcal vaccines are usually advised.
• Safety with anaesthesia: Always tell every doctor, dentist and anaesthetist about your diagnosis and your heart, and carry your reports.
• Never ignore fainting, dizziness or a very slow heartbeat. See a doctor the same day.
• Emotional support: Living with a condition that is both slow and risky can be worrying. Talking to others and to a counsellor helps.

Family Testing and Planning

Once the exact gene change is found, relatives can be tested. For X-linked types, mothers, sisters and female relatives can be tested to see whether they are carriers, and carriers need heart checks. For LMNA-related EDMD, close relatives, even those without symptoms, should have heart checks, because heart rhythm problems can appear without muscle symptoms. A genetic counsellor can explain the risk for each family member and the options for future pregnancies, which are always the family's own choice.

EDMD in Pakistan

In Pakistan, EDMD can be missed because the features are scattered: tight elbows may be thought of as a joint problem, toe walking as a habit, and fainting as weakness or low blood pressure. A family may include a young relative with a pacemaker or an unexplained sudden death, and nobody connects it with a muscle condition. Heart rhythm testing, cardiac devices and genetic testing are mostly available in larger cities and can be costly. If a child or young person has tight elbows or ankles together with muscle weakness, or any family member has a pacemaker or heart rhythm problems at a young age, please ask a neurologist about EDMD and a cardiologist for an ECG and echocardiogram. MDP is collecting patient data on its registration portal, so please register if you or a family member has EDMD or another muscular dystrophy.

Frequently Asked Questions

Why does a muscle disease affect the heart?

The heart is a muscle, and the genes that cause EDMD are important in both skeletal and heart muscle. The heart's electrical system is especially sensitive.

Is EDMD the same as Duchenne?

No. Duchenne is caused by the DMD gene and mainly causes fast-progressing muscle weakness in boys. EDMD is caused by other genes, and it progresses slowly in the muscles, with early joint tightness and heart conduction problems.

Will I definitely need a pacemaker?

Not everyone, but many people with EDMD, particularly X-linked EDMD1, will need one at some point. Regular heart monitoring tells the cardiologist when.

Can women have EDMD?

Women who carry X-linked EDMD genes are usually carriers, and they can develop heart problems later, so they should have heart checks. LMNA-related EDMD, which is autosomal dominant, affects men and women equally.

Which test confirms EDMD?

A genetic test (EDMD gene panel). Heart tests such as ECG, Holter and echocardiogram are done alongside it.

What is the outlook?

Muscle weakness usually progresses slowly. The outlook depends mostly on the heart, and early diagnosis, regular monitoring and a pacemaker or defibrillator when needed can prevent serious events. We do not have reliable survival data for Pakistan.

Is there a cure?

Not yet. Research is ongoing, particularly for LMNA-related heart disease.

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Protect the Heart, Protect the Person

Emery-Dreifuss muscular dystrophy is slow in the muscles but not harmless in the heart. A correct diagnosis, regular heart checks and a pacemaker or defibrillator when needed can change the outcome of a whole family. If you recognise tight elbows, toe walking and muscle weakness together with fainting, a slow heartbeat or a family history of pacemakers, ask your doctor about EDMD. Follow the MDP blog for our guides on each type of muscular dystrophy, and share this article with someone who may need it.

Sources and Further Reading

• GeneReviews, Emery-Dreifuss Muscular Dystrophy
• MedlinePlus Genetics, Emery-Dreifuss muscular dystrophy
• Muscular Dystrophy UK, Emery-Dreifuss muscular dystrophy (EDMD)
• Update of emerinopathies' clinical-genetic spectrum: the French network experience, PubMed Central
• Clinical aspects of Emery-Dreifuss muscular dystrophy, Nucleus

Medical disclaimer: This article is for awareness and education only. It is not a substitute for professional medical advice, diagnosis or treatment. Please consult a qualified doctor about any medical concern. If you or someone else faints or has chest pain, seek emergency care immediately.